Safety lock for vehicle doors



April 27, 1954 J. N. BETHUNE SAFETY LOCK FOR VEHICLE DGORS Filed July l, 1949 [MIEI Patented Apr. 27, 1954 UNITED STATES FATENT OFFICE 3 Claims.

This invention relates to and has for an object the provision of a novel, efcient and simple safety lock for automobile doors by means of which, when employed in connection with conventional door locks, the doors of automobiles may not be accidentally or designedly opened from the inside, as by children confined in the rear part of an automobile, or unauthorizedly from the outside.

In the consideration of my invention, it may be understood that modern sedan automobiles of the four-door type are usually provided with buttons on the window ledges of the doors which are either depressible or liitable for locking the doors against opening from the outside and reversibly operable for rendering the doors openable by movement of the internal or external door handles. In some cases, the handles and door latches are so connected that the internal handles when moved in a door opening direction will unlock the doors while the external handles are ineffective for such purpose.

In all cases, the doors may be readily unlocked from the inside by movement of the handles or latch buttons and because of this fact children, when conned in the rear part of the car, are prone to tamper with the door handles and thereby either accidentally or designedly open a door, perhaps while the car is in motion, resulting in frequent serious injury.

It is, therefore, an object of this invention to provide a safety lock which is equally applicable to and in connection with different forms of door locks, latches and handles for preventing accidental or unauthorized opening of the doors of cars and without changing or impairing the locking and latching means provided on cars of modern design,

With the aforesaid and other objects in view, as will hereinafter appear, I have shown a preferred form of locking mechanism embodying my improvements in the annexed drawing, in which:

Fig. 1 is an elevational view of a typical automobile door locking mechanism with my auxiliary lock operatively applied thereto;

Fig. 2 is an enlarged sectional elevation of my latch arranged to lock when in uppermost position;

Fig. 3 is a section plan of the same on line 3-3 of Fig. 2;

Fig. 4 is a side elevational View of a special key for locking and unlocking my auxiliary lock;

Fig. 5 is a bottom view of the key as seen in the plane of line 5-5 of Fig. 4;

6 is a sectional elevation of a modified form of mechanism arranged to be depressed to its lowermost position for locking a door;

Fig. 7 is a sectional plan of the same on line 'E--l of Fig. 6.

Referring rst to Fig. l, it will be noted that I have shown a typical modern door lock assembly generally represented at L and mounted on a door D below the window ledge D. While the details of unit L are not specically important to my invention, it is well to understand that said unit includes a suitable base I on which a rotatable locking member 2 is mounted at the leading edge 3 of door D and is adapted for operation as by means of an actuator Il pivoted at 5 on base I and connected as by means of elements 5 to member 2. Actuator 4 is connected by a bar 6 to the internal door handle (not shown) and also with my auxiliary lock L through the typical rod l of unit L. Rod has a portion 8 at its lower end which slides in an inclined slot S of a fixed plate IQ of unit L and is adapted to selectively seat in a peripheral groove H of actuator 4. Thus, when rod 'l is pulled upwardly, its portion 8 will disengage groove ll and permit rotation of actuator t when the door handles are properly turned. When. however, rod l is thrust downwardly, its part 3 seats in groove H and prevents rotation of actuator i and member 2, thereby preventing the opening of door D.

In lieu of the usual button on the upper end of rod l above the door ledge D', I provide the auxiliary safety locking unit L which operates and controls the unit L in the same manner as when the usual operating button (not shown) is xed to rod l. In addition, however, unit L includes relatively xed and movable locking members i5 and I6l enclosed in a suitable housing I1 as shown in Figs. 6 and 7, or corresponding members i5', H5 and Il', as shown in Figs. 2 and 3.

The form of unit shown in Figs. 6 and 7 has the housing Il of inverted cup shape and a chamber i8 into the bottom of which the upright body i9 of member l5 telescopically lits and a closed uppei1 end 2B. Member I5 has a bottom ange 2i adapted to overlie door ledge D and housing ll has a larger flange 22 recessed to receive and overlying ange 2l of member i5. Screws 23 extend through flanges 2| and 22 and into door ledge D and serve to iirmly but detachably hold unit L in position on door D. Member l5 is axially bored at 24 to receive the upwardly extended portion of rod 'I and the upper end portion 25 of rod l is threaded to detachably receive and support the movable locking member I6.

Member I6 is normally urged upwardly to either locking or unlocking position, as the case may be, by means of a spring 26 in chamber I8 and compressed between member I5 and an annular flange 2l at the top of member I6. As shown in Fig. 7, member I5 has a plurality of alternating inwardly extended tongues 28 and grooves 29 extended entirely therethrough and a shallow recess 36 at the bottom thereof While member I6 has correspondingly formed tongues 3l matching grooves 29, and spaces 32 matching tongues 28.

Thus, when the tongues 3i are aligned with grooves 29, the member i6 may be slidably moved in body I9 of member I5 to the extreme positions where they will either overlie or underlie body I9 and when slightly rotated at either extreme position, will be held against axial movement in either locking or unlocking positions and, of course, will similarly hold rod 'I either in or out of engagement with actuator ll, as may be desired.

The modified form of unit L', of Fig. 2, is substantially similar to that of Fig. 6 only in the forms of the number I6' and housing II. The housing has a smaller bore I8 than chamber I8 of the unit of Fig. 6 and member I6 is internally bored at I6 a to receive a spring 26. The housing I'I and member I5 have flanges 22 and 2l', respectively, through which screws 23 extend for attaching the unit to door ledge D. f

Member I6 has tongues 3| and grooves 29' are formed in member I5 in which the tongues 3i are slidable into and upwardly from the recesses 36' at the bottom of the unit.

In each form of unit L', the member I6 or i6 has a short upright extension 33 within an opening 34 in the top of the housing Il or I'I with a transversely extended pin 35 projecting at opposite ends therefrom for receiving a special type of key K, as shown in Figs. 4 and 5.

Said key has a wing head 36 and a cylindrical shank 31 which is bored at 38 to receive extension 33 and diametrically slotted at 33 to receive the extended portions of pin 35 when shank 31 is inserted in opening 34 of the housing.

Hence, the key K is eiective for locking the member I6 or I6 in either extreme position thereof for correspondingly setting the actuator 4 in locked or unlocked position, as may be desired. As the key is inserted in opening 34 of the housing with bore 38 over extension 33 and pin 35 in slots 39, the member I6 or I6 may be rotated on rod 'i suiiiciently to register its tongues 3l or 3l' with the grooves 29 or 2S of member I5 or I5' and then by applying pressure to the key, the member I6 or I6 may be depressed together with rod 'I to an extent whereat the tongues 3| or 3l will be in the recess 30 or 36' and by again turning the key and member I6 or I6 slightly, the tongues 3| or 3i thereof will underlie the body I9 of member I5 or I5.

t is preferable to normally maintain unit L in actuator locking position, whether the member I6 or I6 be downmost or uppermost in position. Hence, in such case, it is necessary to use key K for unlocking the actuator as well as for locking the same.

It will be apparent that even though members I6 and I5, or their counterparts I6 and I5', are arranged in registration for relatively slidable movement against the tension of spring 26 or 26', it is still necessary to depress or extend the member I6 or I6 by key K.

`As shown in Figs. 2 and 6, the members I6 and I6 are constantly urged upwardly, but it is lquite apparent that, for example, if spring 26 in Fig. 6 were a tension spring instead of a compression spring and its uppermost coil were suitably attached to ange 21 of member I6 and the lowermost coil thereof attached to member I5, said spring would pull member I6 downwardly to locking plane at the bottom of member I5. When spring 26 is constituted as a tension spring, the slot 39 in key K should be formed as a bayonet slot and to such end may have a right angular extension 46 (Fig. 4) so as to engage pin 35 and lift member I6 against the tension of its spring to the unlocking plane at the top of member I5.

The arrangement of the locking members I5 and IS in housing II, or their counterparts, as otherwise shown, is such that the member I6 can not be rotated or depressed accidentally and even with improvised implements, the rotation and depression or extension would be difcult and due to such facts, full safety to children riding in the rear compartment of a car is provided.

Of course, the position of rod l influences the position of the actuator f. which, in turn, either holds the door latch 2 locked or unlocked.

Thus, I have provided a novel, simple and efficient auxiliary safety locking mechanism particularly adapted for locking car doors against accidental or unauthorized opening of a door and is readily applicable to locking mechanisms of different types but equal effect and which Will occupy but slightly more, if any, space than the conventional push or pull button types of manually operable locks.

What I claim is:

l. A locking mechanism comprising: a housing, a stationary locking member therein formed with concentric tongues and grooves; a coaxial movable locking member formed with tongues and grooves complementary with those of the stationary member whereby said movable member may be moved through the stationary member to locking and unlocking positions at opposite ends of the stationary member; and means borne by the movable member for receiving a key whereby the movable member may be rotated into and from positions of registration with'and for movement through the stationary member when actuated by said key for lockingly engaging the stationary member, said locking members being arranged to coaxially embrace an vaxially movable lockable member to which the movable member is adapted to be attached for locking the lockable member against movement in a given direction.

2. A locking mechanism comprising: a housing, a stationary locking member therein formed with concentric tongues and grooves; a coaxialV movable locking member formed with tongues and grooves complementary with those of the stationary member whereby said movable member may be moved through the stationary member to locking and unlocking positions at opposite ends of the stationary member; means borne by the movable member for receiving a key whereby the movable member may be rotated into vand from positions of registration with and for movement through the stationary member when actuated by said key for lockingly engaging the stationary member, said locking members being arranged to coaxially embrace an axially movable lockable member to which the movable member is `adapted to be attached for locking the lockable member against movement in a given direction; and spring means between said locking members normally urging the movable locking member to locked position.

3. A locking mechanism comprising: a, housing, a stationary locking member therein formed with concentric tongues and grooves; a coaxial movable locking member formed with tongues and grooves complementary with those of the stationary member whereby said movable member may be moved through the stationary member to locking and unlocking positions at opposite ends of the stationary member; means borne by the movable member for receiving a key whereby the movable member may be rotated into and from positions of registration with and for movement through the stationary member When actuated by said key for lockingly engaging the stationary member, said locking members being arranged to coaxially embrace an axially movable lockable member to which the movable member is adapted to be attached for locking the lockable member against movement in a given direction; spring means between said locking members normally urging the movable locking member to normally locked position; said housing enclosing all of said elements against access except by means of an operating key.

References Cited in the le of this patent UNITED STATES PATENTS 

